Go to SETTINGS > Your Team > Team Capacity Settings. For each employee, per project role, set:

Capacity is set per month using the month picker at the top of the page. If a month has no capacity saved for it, it shows the values from the last month that was saved, and keeps showing those same values for every month after until a new one is saved specifically. An indicator next to the month picker shows whether the values you're viewing were saved for this exact month or are being inherited, and if inherited, which month they're inherited from.

Your weekly capacity and target drive the utilization dial on the time entry grid and the capacity dial on the Resource Scheduler.

Capacity doesn't vary based on Payroll Type (Hourly/Salaried/Contracted) - it's the same weekly-hours model for everyone.

When you update an employee's role, rate, capacity, or utilization target, you can apply the change to the selected month and every future month that already has its own saved values, so the change can't be silently undone later by an older future month that was set before it. Months before the employee's hire date are skipped.

If the month you're changing is currently inheriting rather than having its own saved values, you'll first be prompted to save the whole team's current values for that month before the change is applied - this tells you how many people will be affected, and won't proceed if anyone is missing a project role, naming who.

SETTINGS > Your Team > Team Capacity Settings also has an option to clear every future saved month for the entire team at once. This permanently deletes those saved values - the current month and anything earlier are not affected - and can't be undone. A confirmation naming each month that will be cleared is shown before it runs.